电力建设Issue(11)：132-138,7.DOI:10.3969/j.issn.1000-7229.2014.11.023
660 MW超超临界锅炉末级再热器氧化皮大面积剥落原因分析
Cause Analysis of Massive Oxidation Scale Exfoliation from Final Reheater in 660 MW Ultra-Supercritical Boiler
姚兵印 1李志刚 1党黎军 1张志博 1侯召堂 1唐丽英1
作者信息
- 1. 西安热工研究院有限公司，西安市710032
- 折叠
摘要
Abstract
To understand the reason of massive oxidation scale exfoliation from the final reheater (RH)tubes of two 660 MW ultra-supercritical (USC)boilers after operating for 1.7 ×104 to 20 ×104 h,TP347H tubes cut from the final superheater (SH),3rd SH (rear plate superheater),and final RH were investigated for chemical compositions analysis, tensile testing at ambient temperature,hardness test,metallographic examination,etc.Microstructure analysis shows that there is a layer of fine grain zone (No.9-10 grade grain size)on the inner surface of the 3rd SH and the TP347H tubes in final SH,but only the coarse grain zone can be seen in final RH.The presence of the coarse grain zone on inside surface of RH tubes causes the massive oxidation scale exfoliation from RH tubes.The grain size of TP347 H tubes has great influence on the forming speed of oxide scale on the inside surface.It is found that fine grain size and high density grain boundaries can increase “short way”Cr element diffusion rates in the TP347 H austenitic steel,thus increasing the resistance to steam oxidation during operating at high temperature.Finally,suggestions on material selections for 600 ℃temperature class USC boiler tubes were presented for consideration.关键词
超超临界机组/末级再热器/氧化皮/晶粒度/抗蒸汽氧化能力Key words
ultra-supercritical unit/final reheater/oxide scale/grain size/resistance to steam oxidation分类
信息技术与安全科学引用本文复制引用
姚兵印,李志刚,党黎军,张志博,侯召堂,唐丽英..660 MW超超临界锅炉末级再热器氧化皮大面积剥落原因分析[J].电力建设,2014,(11):132-138,7.
